The instability of a layer of fluid heated below and subject to the simultaneous action of a magnetic field and rotation. Il

Abstract

The theory described in an earlier paper (Chandrasekhar 1954) is extended to include the possibility that a layer of fluid heated below and subject to the simultaneous action of a magnetic field and rotation can become unstable via a marginal state of purely oscillatory motions. It is shown that depending on the value of the non-dimensional parameters Q and T and the coefficients of kinematic viscosity and thermal and electrical conductivities, instability can set in either as convection or as overstability. Numerical results are derived for the case when the physical constants are those applicable to mercury at ordinary room temperatures. The nature of the effects one may expect to observe are illustrated.